Reorganize configuration into modular directory structure

- Create modules/ directory for Nix configuration modules
- Create config/ directory for configuration files
- Move nvim.nix, tmux.nix, zsh.nix to modules/
- Move p10k.zsh to config/
- Update flake.nix import paths to reference new structure
- Update zsh.nix p10k.zsh path reference
- Update README.md architecture documentation
- Keep tmux.sh at root for easy accessibility

This provides better separation between Nix modules and config files
while maintaining a clean, scalable structure.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

modules/nvim.nix

@@ -0,0 +1,200 @@
+{ pkgs, ... }:
+
+{
+  programs.nixvim = {
+    enable = true;
+    defaultEditor = true;
+
+    # Global settings
+    globals.mapleader = " ";
+
+    # Vim options
+    opts = {
+      number = true;
+      relativenumber = false;
+      expandtab = true;
+      shiftwidth = 2;
+      tabstop = 2;
+      smartindent = true;
+      wrap = false;
+      linebreak = true;      # Don't break words when wrapping
+      breakindent = true;    # Preserve indentation when wrapping
+      termguicolors = true;
+    };
+
+    # Enable filetype detection
+    viAlias = true;
+    vimAlias = true;
+
+    # Gruvbox colorscheme with hard contrast
+    colorschemes.gruvbox = {
+      enable = true;
+      settings = {
+        contrast = "hard";  # Makes background much darker (#1d2021 instead of #282828)
+        background = "dark";
+      };
+    };
+
+    # Plugins
+    plugins = {
+      # File explorer
+      nvim-tree = {
+        enable = true;
+        # NixVim nvim-tree uses extraConfig for detailed settings
+      };
+
+      # Syntax highlighting
+      treesitter = {
+        enable = true;
+        settings = {
+          highlight = {
+            enable = true;
+            additional_vim_regex_highlighting = true;
+          };
+          indent = {
+            enable = true;
+          };
+          ensure_installed = [];  # Managed by Nix
+          auto_install = false;
+        };
+        grammarPackages = with pkgs.vimPlugins.nvim-treesitter.builtGrammars; [
+          bash c cpp css dockerfile go html javascript json lua markdown nix python rust typescript yaml
+        ];
+      };
+
+      # Status line with gruvbox theme and relative paths
+      lualine = {
+        enable = true;
+        settings = {
+          options = {
+            theme = "gruvbox_dark";
+            component_separators = { left = "|"; right = "|"; };
+            section_separators = { left = " "; right = " "; };
+          };
+          sections = {
+            lualine_c = [{ __unkeyed-1 = "filename"; path = 1; }];
+          };
+        };
+      };
+
+      # Web dev icons
+      web-devicons = {
+        enable = true;
+      };
+
+      # Markdown rendering
+      render-markdown = {
+        enable = true;
+      };
+    };
+
+    # Extra plugins that don't have dedicated modules
+    extraPlugins = with pkgs.vimPlugins; [
+      vim-fugitive
+    ];
+
+    # Keymaps
+    keymaps = [
+      # File explorer
+      {
+        mode = "n";
+        key = "<leader>e";
+        action = ":NvimTreeToggle<CR>";
+        options = { desc = "Toggle file explorer"; };
+      }
+
+      # Basic keymaps
+      {
+        mode = "n";
+        key = "<leader>w";
+        action = ":w<CR>";
+        options = { desc = "Save file"; };
+      }
+      {
+        mode = "n";
+        key = "<leader>q";
+        action = ":q<CR>";
+        options = { desc = "Quit"; };
+      }
+
+      # System clipboard keymaps
+      {
+        mode = ["n" "v"];
+        key = "<leader>y";
+        action = "\"+y";
+        options = { desc = "Copy to system clipboard"; };
+      }
+      {
+        mode = "n";
+        key = "<leader>p";
+        action = "\"+p";
+        options = { desc = "Paste from system clipboard"; };
+      }
+      {
+        mode = "v";
+        key = "<leader>p";
+        action = "\"+p";
+        options = { desc = "Replace selection with system clipboard"; };
+      }
+
+      # System integration
+      {
+        mode = "n";
+        key = "<leader>o";
+        action = ":silent !open %<CR>";
+        options = { desc = "Open file with system default app"; };
+      }
+      {
+        mode = "n";
+        key = "<leader>f";
+        action = ":silent !open -R %<CR>";
+        options = { desc = "Show current file in Finder"; };
+      }
+
+      # Git keymaps (vim-fugitive)
+      {
+        mode = "n";
+        key = "<leader>gs";
+        action = ":Git<CR>";
+        options = { desc = "Git status"; };
+      }
+      {
+        mode = "n";
+        key = "<leader>gd";
+        action = ":Git diff<CR>";
+        options = { desc = "Git diff"; };
+      }
+      {
+        mode = "n";
+        key = "<leader>gc";
+        action = ":Git commit<CR>";
+        options = { desc = "Git commit"; };
+      }
+      {
+        mode = "n";
+        key = "<leader>gp";
+        action = ":Git push<CR>";
+        options = { desc = "Git push"; };
+      }
+
+      # Markdown rendering
+      {
+        mode = "n";
+        key = "<leader>md";
+        action = ":RenderMarkdown toggle<CR>";
+        options = { desc = "Toggle markdown rendering"; };
+      }
+    ];
+
+    # Additional Lua configuration for plugins that need custom setup
+    extraConfigLua = ''
+      -- Nvim-tree setup with filters
+      require("nvim-tree").setup({
+        filters = {
+          dotfiles = true,      -- Hide dotfiles by default (H to toggle)
+          git_ignored = false,  -- Show gitignored files by default (I to toggle)
+        },
+      })
+    '';
+  };
+}